I just got off the horn with support for an hour because I thought it important that they know some:
1. CSS classes are injected at view use of form on the creation/edit/view of an ItemType.
2. Inline styles are injected with a default (for at least dropdowns) width of 89px;
In the end you can spend all day perfecting the layout of a form in the WYSIWYG-ish editor for Forms and then you go to create the related ItemType only to see all your efforts crash and burn because of the injected CSS classes and inline styles.
The call went fine, but in the end it was a case of: You found a workaround so have a nice day and feel free to file specific CSS changes as a change request with Aras.
Okay, well, I can go and add these to the main.css or the default.css and they'll never show. This, of course, is because the minified css is what is being loaded - even if you've updated web.config to an new number (and you can see that number in the salt=NEW_NUMBER of the URL - learned that today!).
But, guess what? There is no re-minification. I've been digging through the rollup used in the Client, but I am not finding where the minified command happens? The package.json doesn't specifically have any package I've used for this. So... other than editing minified files (I use sed to slap on overrides at the end of whatever.css as a work-around, and I don't like needing to do that because I'm just overriding other styles defined earlier in said CSS...).
My ask is: Where are CSS minified? Also, if this isn't something kicked off by version change in web.config, well, why not!?